High latency seen, but not in qos statistics volume latency show
Applies to
- Clustered Data ONTAP 8.3
- ONTAP 9
- CIFS or NFS connections
Issue
High latency is seen in Unified Manager, but running "qos statistics volume latency show" does not indicate a delay.
Example for data1 volume:
nas-cm95::> qos statistics volume performance show Workload ID IOPS Throughput Latency --------------- ------ -------- ---------------- ---------- -total- - 78 0.07KB/s 111.01ms data1-wid30897 30897 78 0.07KB/s 521.01ms -total- - 84 0.07KB/s 111.01ms data1-wid30897 30897 84 0.07KB/s 521.01ms -total- - 158 0.08KB/s 111.01ms data1-wid30897 30897 158 0.08KB/s 521.01ms -total- - 158 0.08KB/s 111.01ms data1-wid30897 30897 158 0.08KB/s 521.01ms
nas-cm95::> qos statistics volume latency show Workload ID Latency Network Cluster Data Disk QoS NVRAM Cloud FlexCache SM Sync --------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- -total- - 367.00us 155.00us 3.00us 161.00us 0ms 0ms 0.00us 0ms 0ms 0ms data1-wid30897 30897 312.00us 160.00us 0ms 152.00us 0ms 0ms 0.00us 0ms 0ms 0ms -total- - 902.00us 153.00us 5.00us 151.00us 8.00us 0ms 0.00us 0ms 0ms 0ms data1-wid30897 30897 307.00us 150.00us 0ms 149.00us 8.00us 0ms 0.00us 0ms 0ms 0ms -total- - 1139.00us 149.00us 7.00us 141.00us 9.00us 0ms 0.00us 0ms 0ms 0ms data1-wid30897 30897 284.00us 145.00us 0ms 138.00us 1.00us 0ms 0.00us 0ms 0ms 0ms -total- - 343.00us 147.00us 5.00us 145.00us 0ms 0ms 0.00us 0ms 0ms 0ms data1-wid30897 30897 286.00us 146.00us 0ms 140.00us 0ms 0ms 0.00us 0ms 0ms 0ms
A Unified Manager alert is demonstrated below where it can show the latency in the Network processing center:
There may be no delay centers showing any significant latency, but client side reports high latency.